Display

ABSTRACT

A display includes: a display section that includes first pixels to nth pixels and displays perspective images assigned to the first to nth pixels; and a display control section that partitions the display section into sub-regions and performs display control on pixels in each of the sub-regions, independently, to vary a correspondence relationship between the first to nth pixels and the perspective images for each of the sub-regions. The display control section assigns a first perspective image to two pixels of the first pixel to the nth pixel and assigns a second perspective image to other two pixels of the first pixel to the nth pixel, in each of the sub-regions. The display control section adjusts a luminance level of one or both of the two pixels and a luminance level of one or both of the other two pixels in each of the sub-regions.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application claims priority to Japanese Priority PatentApplication JP 2011-147210 filed in the Japan Patent Office on Jul. 1,2011, the entire content of which is hereby incorporated by reference.

BACKGROUND

The present application relates to a display performing stereoscopicdisplay by a naked-eye system with use of a parallax separationstructure such as a parallax barrier.

Techniques of performing stereoscopic display include a glass systemwith use of glasses for stereoscopic vision and a naked-eye systemcapable of achieving stereoscopic vision by naked eyes without glassesfor stereoscopic vision. A typical glass system is a shatter glasssystem using shutter glasses with a left-eye shutter and a right-eyeshutter. In the shutter glass system, a left-eye parallax image and aright-eye parallax image are alternately displayed on a two-dimensionaldisplay panel at high speed in a frame-sequential manner. Then, theleft-eye shutter and the right-eye shutter are alternately opened andclosed in synchronization with switching of the parallax images to allowonly the left-eye parallax image and the right-eye parallax image toenter a left eye and a right eye of a viewer, respectively, therebyachieving stereoscopic vision.

On the other hand, typical naked-eye systems include a parallax barriersystem and a lenticular lens system. In the parallax barrier system andthe lenticular lens system, parallax images for stereoscopic vision (aright-eye parallax image and a left-eye parallax image in the case oftwo perspectives) which are spatially separated from one another aredisplayed on a two-dimensional display panel, and the parallax imagesare separated by parallax in a horizontal direction by a parallaxseparation structure to achieve stereoscopic vision. In the parallaxbarrier system, as the parallax separation structure, a parallax barrierhaving slit-like openings is used. In the lenticular system, as theparallax separation structure, a lenticular lens including a pluralityof cylindrical split lenses arranged side-by-side is used.

SUMMARY

In a naked-eye system using a parallax separation structure, there is anissue that when a view position of a viewer is out of a predetermineddesign region, proper stereoscopic vision is not achievable. Moreover,Japanese Unexamined Patent Application Publication No. H09-50019discloses a display capable of reducing a preferred viewing distance indesign; however, a too short preferred viewing distance may cause a toonarrow space between a parallax separation structure and a displaysection displaying an image, thereby causing difficulty inmanufacturing.

It is desirable to provide a display capable of performing optimumstereoscopic display according to a view position.

According to an embodiment of the application, there is provided adisplay including: a display section including a plurality of firstpixels to a plurality of nth pixels, where n is an integer of 4 or more,and displaying a plurality of perspective images assigned to the firstto nth pixels; and a display control section partitioning the displaysection into a plurality of sub-regions and performing display controlon pixels in each of the sub-regions, independently, thereby to vary acorrespondence relationship between the first to nth pixels and theperspective images for each of the sub-regions. The display controlsection assigns a first perspective image to two pixels of the firstpixel to the nth pixel and assigns a second perspective image to othertwo pixels of the first pixel to the nth pixel, in each of thesub-regions, and the display control section adjusts a luminance levelof one or both of the two pixels and a luminance level of one or both ofthe other two pixels in each of the sub-regions.

In the display according to the embodiment of the application, controlis performed to vary the correspondence relationship between the firstto nth pixels and the perspective images for each of the sub-regions.Moreover, the luminance level of one or both of the two pixels and theluminance level of one or both of the other two pixels are adjusted ineach of the sub-regions.

In the display according to the embodiment of the application, thedisplay control is performed on pixels of the display section in each ofthe sub-regions, independently, thereby to vary the correspondencerelationship between the first to nth pixels and the perspective imagesfor each of the sub-regions, and the luminance level of one or both ofthe two pixels and the luminance level of one or both of the other twopixels are adjusted in each of the sub-regions. Therefore, optimumstereoscopic display according to a view position is allowed to beperformed.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, and are intended toprovide further explanation of the application as claimed.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate embodiments and,together with the specification, serve to explain the principles of theapplication.

FIG. 1 is a block diagram illustrating an example of a wholeconfiguration of a display according to an embodiment of theapplication.

FIG. 2 is a sectional view illustrating a configuration example in thecase where stereoscopic display with four perspectives is performed inthe display illustrated in FIG. 1.

FIG. 3 is a sectional view illustrating a reference example in the casewhere stereoscopic display with two perspectives is performed.

FIG. 4 is an explanatory diagram of a preferred viewing distance.

FIG. 5 is an explanatory diagram of viewable pixels in the case where aview position of a viewer is located in a first light-convergence regionwhen stereoscopic display with four perspectives illustrated in FIG. 2is performed.

FIG. 6 is an explanatory diagram of viewable pixels in the case wherethe view position of the viewer is located in a predetermined distancerange from the first light-convergence region when stereoscopic displaywith four perspectives illustrated in FIG. 2 is performed.

FIG. 7 is an explanatory diagram of viewable pixels in the case wherethe view position of the viewer is located in a predetermined distancerange from the first light-convergence region and a fourthlight-convergence region when stereoscopic display with fourperspectives illustrated in FIG. 2 is performed.

FIG. 8 is a first explanatory diagram of viewable pixels in the casewhere the view position of the viewer is located at a distance Z0/2equal to a half of a preferred viewing distance (a second distance Z0)with four perspectives when stereoscopic display with four perspectivesillustrated in FIG. 2 is performed.

FIG. 9 is a second explanatory diagram of viewable pixels in the casewhere the view position of the viewer is located at the distance Z0/2equal to a half of the preferred viewing distance (the second distanceZ0) with four perspectives when stereoscopic display with fourperspectives illustrated in FIG. 2 is performed.

FIG. 10 is an explanatory diagram, where a part (A) illustrates pixelnumbers viewable by a right eye and a luminance distribution in aviewing state illustrated in FIG. 9, and a part (B) illustrates pixelnumbers viewable by a left eye and a luminance distribution in theviewing state illustrated in FIG. 9.

FIG. 11 is an explanatory diagram, where a part (A) illustrates acorrespondence relationship between a plurality of sub-regionsconfigured to allow stereoscopic display with two perspectives at thedistance Z0/2 in a configuration where stereoscopic display with fourperspectives is achievable at the distance Z0 and pixel numbers to whicha right-eye image is assigned in each of the sub-regions, and a part (B)illustrates a correspondence relationship between a plurality ofsub-regions configured in a manner similar to the case of the part (A)and pixel numbers to which a left-eye image is assigned in each of thesub-regions.

FIG. 12 is an explanatory diagram illustrating a luminance distributionof each pixel in two adjacent sub-regions in the case where stereoscopicdisplay illustrated in FIG. 11 is performed.

FIG. 13 is an explanatory diagram of viewable pixels in the case wherethe view position of the viewer is located at a distance Z0/2 equal to ahalf of a preferred viewing distance with five perspectives whenstereoscopic display with five perspectives is performed.

FIG. 14 is an explanatory diagram, where a part (A) illustrates pixelnumbers viewable by a right eye and a luminance distribution in aviewing state illustrated in FIG. 13, and a part (B) illustrates pixelnumbers viewable by a left eye and a luminance distribution in theviewing state illustrated in FIG. 13.

FIG. 15 is an explanatory diagram, where a part (A) illustrates acorrespondence relationship between a plurality of sub-regionsconfigured to allow stereoscopic display with two perspectives at thedistance Z0/2 in a configuration where stereoscopic display with fiveperspectives is achievable at the distance Z0 and pixel numbers to whicha right-eye image is assigned in each of the sub-regions, and a part (B)illustrates a correspondence relationship between a plurality ofsub-regions configured in a manner similar to the case of the part (A)and pixel numbers to which a left-eye image is assigned in each of thesub-regions.

FIG. 16 is an explanatory diagram of occurrence of moiré at the distanceZ0/2, where a part (A) illustrates pixel numbers viewable by a right eyeand a luminance distribution in the viewing state illustrated in FIG. 9,and a part (B) illustrates pixel numbers viewable by a left eye and aluminance distribution in the viewing state illustrated in FIG. 9.

FIGS. 17A and 17B are explanatory diagrams illustrating first and secondadjustment methods adopted to suppress occurrence of moiré,respectively.

FIG. 18 is an explanatory diagram, where a part (A) illustrates acorrespondence relationship between a plurality of sub-regions and pixelnumbers to which a right-eye image is assigned in each of thesub-regions, and a part (B) illustrates a correspondence relationshipbetween the plurality of sub-regions and pixel numbers to which aleft-eye image is assigned in each of the sub-regions.

FIG. 19 is an explanatory diagram illustrating the second adjustmentmethod adopted to suppress occurrence of moiré.

DETAILED DESCRIPTION

A preferred embodiment of the present application will be described indetail referring to the accompanying drawings.

[Whole Configuration of Display]

FIG. 1 illustrates a configuration example of a display according to anembodiment of the application. The display includes a detection section1, a display control section 4, an image production section 5, and adisplay section 6. The detection section 1 includes an image pickupsection 2 and a view position evaluation section 3.

The display section 6 is configured of a two-dimensional display such asa liquid crystal display panel, an electroluminescence display panel, ora plasma display. A plurality of pixels are two-dimensionally arrangedon a display screen of the display section 6. Images are displayed onthe display screen of the display section 6 according to a stereoscopicdisplay system of the display. First to nth (where n is an integer of 4or more) numbers corresponding to first to nth perspectives,respectively, in stereoscopic display are assigned to the plurality ofpixels (or sub-pixels) of the display section 6.

The display performs stereoscopic display by a naked-eye system, and thestereoscopic display system is a system using a parallax separationstructure such as a parallax barrier system or a lenticular lens system.In the case of the lenticular lens system, as the parallax separationstructure, for example, a lenticular lens including a plurality ofcylindrical split lenses arranged side-by-side is used. A parallaxcomposite image created by combining parallax images (perspectiveimages) corresponding to a plurality of perspectives in one screen isdisplayed on the display section 6. In other words, a plurality ofperspective images are spatially separated and displayed. As will bedescribed later, the display varies the number of perspective imagesdisplayed on the display section 6 according to a view position of aviewer. For example, in the case where the view position of the vieweris located at a first distance Z0/2 (refer to FIG. 9 or the like whichwill be described later), a left-eye image and a right-eye image whichare parallax images corresponding to two perspectives, i.e., left andright perspectives are displayed as the plurality of perspective images.Moreover, for example, in the case where the view position of the vieweris located at a second distance Z0 which is a normal preferred viewingdistance, parallax images corresponding to a plurality of perspectives,for example, first to fourth perspective images are displayed as theplurality of perspective images (refer to FIG. 2 or the like which willbe described later).

In the embodiment, the case where stereoscopic display by the parallaxbarrier system is performed will be described below as an example. Inthe case of the parallax barrier system, for example, as illustrated inFIG. 2, a barrier device 7 is used as the parallax separation structure.The barrier device 7 has opening sections 8 allowing light to passtherethrough and shielding sections 9 shielding light. The barrierdevice 7 may be a fixed parallax barrier or a variable parallax barrier.In the case of the fixed parallax barrier, for example, a parallaxbarrier formed by forming a pattern including the opening sections 8 andthe shielding sections 9 with use of metal in a thin-film shape on asurface of a transparent plane parallel plate (base) is allowed to beused. In the case of the variable parallax barrier, for example,patterns of the opening sections 8 and the shielding sections 9 areallowed to be selectively formed with use of, for example, a displayfunction (a light modulation function) by backlight system liquidcrystal display devices. It is to be noted that FIG. 2 illustrates anexample in which the barrier device 7 is disposed on a display plane ofthe display section 6; however, the barrier device 7 may be disposed ona back plane of the display section 6. For example, in the case where abacklight system liquid crystal display panel is used as the displaysection 6, the barrier device 7 may be disposed on a back plane of theliquid crystal display panel between a backlight and the liquid crystaldisplay panel.

The image pickup section 2 takes an image of a viewer. The view positionevaluation section 3 evaluates the view position of the viewer(evaluates the viewing distance from the display section 6 and aposition in an in-plane direction parallel to the display plane) byanalyzing the image taken by the image pickup section 2. The viewposition is allowed to be detected by the detection section 1 with useof, for example, a face tracking technique. It is to be noted that theviewing distance is typically a distance from the display plane of thedisplay section 6 to a central position between both eyes of the viewer.

The display control section 4 controls an image to be displayed on thedisplay section 6 according to the view position of the viewer detectedby the detection section 1. As will be described later, in the casewhere the view position of the viewer is located at the first distanceZ0/2 from the display section 6, the display control section 4 performsdisplay control on pixels in each of a plurality of sub-regions 31(refer to FIG. 11 or the like which will be described later) of thedisplay section 6, independently, thereby to vary a correspondencerelationship between the first to nth pixels and the perspective images(a left-eye image and a right-eye image) for each of the sub-regions 31.As will be described later, in the case where the view position of theviewer is located at the second distance Z0, the display control section4 assigns the first to nth perspective images as a plurality ofperspective images to the first to nth pixels in an entire screen.

The image production section 5 produces, in response to control by thedisplay control section 4, image data including a plurality ofperspective images that are based on the view position of the viewer tosupply the image data to the display section 6. The display controlsection 4 allows the display section 6 to display the image dataproduced by the image production section 5.

[Principle of Stereoscopic Display at Normal Preferred Viewing Distance(Second Distance Z0)]

FIG. 2 illustrates a principle in the case where stereoscopic displaywith four perspectives is performed in the display. A display principlein the example in FIG. 2 is basically similar to a principle ofstereoscopic display with four perspectives by a parallax barrier systemin related art. First to fourth numbers corresponding to fourperspectives are assigned to a plurality of pixels (or sub-pixels) ofthe display section 6. The display control section 4 assigns first tofourth perspective images as a plurality of perspective images to thefirst to fourth pixels, respectively, in the entire screen of thedisplay section 6. Light beams from the first to fourth pixels of thedisplay section 6 are separated by the opening sections 8 of the barrierdevice 7. The separated light beams reach first to fourthlight-convergence regions 11 to 14 located at the second distance Z0,respectively. In other words, for example, all light beams from thefirst pixels in the entire screen reach the first light-convergenceregion 11 located at the second distance Z0 by a separation function ofthe barrier device 7. Likewise, all light beams from the second tofourth pixels in the entire screen reach respective light-convergenceregions to which corresponding numbers are assigned.

The width of each of the first to fourth light-convergence regions 11 to14 is equal to a pupillary distance E (typically 65 mm) Therefore, aright eye 10R and a left eye 10L of the viewer are located in differentlight-convergence regions, and view different perspective images toachieve stereoscopic vision. For example, in the example in FIG. 2, theright eye 10R of the viewer is located in the second light-convergenceregion 12, and the left eye 10L of the viewer is located in the thirdlight-convergence region 13. In this case, stereoscopic vision isachieved with an image (the second perspective image) created by lightfrom the second pixels and an image (the third perspective image)created by light from the third pixels. In the case where the viewposition is moved in a horizontal direction, different perspectiveimages corresponding to the moved position are viewed to achievestereoscopic vision.

FIG. 3 illustrates a principle in the case where stereoscopic displaywith two perspectives is performed by a related-art system as areference example in comparison with FIG. 2. The principle is basicallythe same as that in the case of stereoscopic display with fourperspectives illustrated in FIG. 2, except that the number ofperspectives is two. In the display section 6, as a plurality of pixels,sub-pixels of RGB are alternately arranged, and first and second numbersare assigned to respective sub-pixels. A first perspective image (aright-eye image) and a second perspective image (a left-eye image) areassigned to the first sub-pixels and the second sub-pixels,respectively, in the entire screen of the display section 6, and thefirst and second perspective images are displayed. Light beams from thefirst sub-pixels and the second sub-pixels in the display section 6 areseparated by the opening sections 8 of the barrier device 7. Theseparated light beams reach the first and second light-convergenceregions 11 and 12 located at the second distance Z0, respectively. Inother words, all light beams from the first pixels in the entire screenreach the first light-convergence region 11 located at the seconddistance Z0 by the separation function of the barrier device 7.Likewise, all light beams from the second pixels in the entire screenreach the second light-convergence region 12 located at the seconddistance Z0. The width of each of the first and second light-convergenceregions 11 and 12 is equal to the pupillary distance E (typically 65 mm)Therefore, the right eye 10R and the left eye 10L of the viewer arelocated in different light-convergence regions, and view differentperspective images to achieve stereoscopic vision.

[Normal Preferred Viewing Distance (Second Distance Z0) in Design]

Referring to FIG. 4, a preferred viewing distance (the second distanceZ0) in design in the case where stereoscopic display based on thedisplay principle illustrated in FIGS. 2 and 3 is performed will bedescribed below. In an example illustrated in FIG. 4, the displaysection 6 is, for example, a backlight system liquid crystal displaypanel, and a backlight 80 is disposed on the back plane of the displaysection 6. The display section 6 includes a first transparent substrate61 and a second transparent substrate 62 which face each other, andincludes a pixel section 63 between the substrates 61 and 62. Thebarrier device 7 is, for example, a transmissive type variable parallaxbarrier device, and includes a first transparent substrate 71 and asecond transparent substrate 72 which face each other, and has openingsections 8 and shielding sections 9 between the substrates 71 and 72. Inaddition, the display section 6 and the barrier device 7 each includesuch as a polarizing plate and an adhesive layer on both surfaces or onesurface thereof.

In FIG. 4, the pupillary distance is E, a pitch between pixels (orsub-pixels) in the display section 6 is P. A gap between the pixelsection 63 of the display section 6 and the opening sections 8 of thebarrier device 7 and between the pixel section 63 and the shieldingsections 9 thereof is G. Moreover, a refractive index of a substrate orthe like disposed between the pixel section 63 and the opening sections8 and between the pixel section 63 and the shielding sections 9 is n. Adistance from a central portion of a surface of the barrier device 7 toa central position between the left eye 10L and the right eye 10R of theviewer is A. In this case, the following relational expression isestablished in design. In the case where stereoscopic display isperformed based on the display principle illustrated in FIGS. 2 and 3,the normal preferred viewing distance (the second distance Z0) in designhas a value according to the following relational expression.A:E=G/n:P

[Relationship Between View Position and Pixel to be Viewed]

FIG. 5 illustrates viewable pixels in the case where the view positionof the viewer is located in the first light-convergence region 11 whenstereoscopic display with four perspectives illustrated in FIG. 2 isperformed. Moreover, FIG. 6 illustrates viewable pixels in the casewhere the view position of the viewer is located in a predetermineddistance range from the first light-convergence region 11. It is to benoted that the barrier device 7 is not illustrated in FIGS. 5 and 6. InFIG. 7 and the following drawings, the barrier device 7 is also notillustrated.

As illustrated in FIG. 5, in the case where the view position of theviewer is located in the first light-convergence region 11, all lightbeams from the first pixels in the entire screen reach the right eye 10R(or the left eye 10L) of the viewer. Moreover, as illustrated in FIG. 6,in the case where the view position is located in a predetermined region20 within a predetermined distance range from the firstlight-convergence region 11, all light beams from the first pixels inthe entire screen reach the right eye 10R (or the left eye 10L) of theviewer.

FIG. 7 illustrates viewable pixels in the case where the view positionof the viewer is located out of the predetermined region 20 in FIG. 6,but in a predetermined distance range from the first light-convergenceregion 11 and the fourth light-convergence region 14. In this case,light beams from the first pixels in a first display region 6A of thedisplay section 6 and light beams from the fourth pixels in a seconddisplay region 6B reach the right eye 10R (or the left eye 10L) of theviewer. In other words, in this case, the right eye 10R (or the left eye10L) of the viewer views not only light beams from the first pixels (thefirst perspective image) but also light beams from the fourth pixels(the fourth perspective image).

Viewable pixels (a perspective image) in the case where, as illustratedin FIG. 7, the view position of the viewer is located out of thepredetermined region 20 are determined by analyzing whichlight-convergence regions light beams having reached an eye are supposedto reach.

FIGS. 8 and 9 illustrate viewable pixels in the case where the viewposition of the viewer is located at a distance (a first distance Z0/2)equal to a half of the preferred viewing distance (the second distanceZ0) with four perspectives. The right eye 10R is located in a firstregion 21 at the first distance Z0/2, and the left eye 10L is located ina second region 22 at the first distance Z0/2. The width of the firstregion 21 and the width of the second region 22 each are equal to thepupillary distance E (typically 65 mm).

In the case where the view position is located at the first distanceZ0/2, as illustrated in FIG. 8, pixels (perspective images) viewed bythe right eye 10R and the left eye 10L of the viewer are different(shifted) by two perspectives from those in the case where the viewposition is located on the preferred viewing distance (the seconddistance Z0) in design. Moreover, as illustrated in FIG. 9, light beamsfrom the first to fourth pixels (the first to fourth perspective images)reach each of the right eye 10R and the left eye 10L.

A part (A) in FIG. 10 illustrates pixel numbers viewable by the righteye 10R and a luminance distribution in a viewing state illustrated inFIG. 9. A part (B) in FIG. 10 illustrates pixel numbers viewable by theleft eye 10L and a luminance distribution in the viewing stateillustrated in FIG. 9. In the viewing state illustrated in FIG. 9, theright eye 10R and the left eye 10L view pixels (perspective images)different from one of four regions to another in the display section 6.The width of each of the four regions is equal to the pupillary distanceE (typically 65 mm) More specifically, as illustrated in the part (A) inFIG. 10, the right eye 10R views the third pixel (the third perspectiveimage), the second pixel (the second perspective image), the first pixel(the first perspective image), and the fourth pixel (the fourthperspective image) in order from an end of the display screen. Moreover,as illustrated in the part (B) in FIG. 10, the left eye 10L views thefirst pixel (the first perspective image), the fourth pixel (the fourthperspective image), the third pixel (the third perspective image), andthe second pixel (the second perspective image) in order from the end ofthe display screen.

[Optimized Stereoscopic Display Method in the Case where View Positionis Located at First Distance Z0/2]

Next, referring to FIGS. 11 and 12, an optimized stereoscopic displaymethod in the case where the view position is located at the firstdistance Z0/2 will be described below. As can be understood from theabove description referring to FIGS. 8 to 10, in the case where the viewposition is located at the first distance Z0/2, proper stereoscopicvision is not achieved while four perspective images, i.e., the first tofourth perspective images are displayed on the display section 6.Therefore, in the embodiment, in the case where the view position islocated at the first distance Z0/2, the display control section 4controls the display section 6 to display two perspective images, i.e.,a right-eye image and a left-eye image instead of the first to fourthperspective images.

A part (A) in FIG. 11 illustrates a correspondence relationship betweena plurality of sub-regions 31 configured to allow stereoscopic displaywith two perspectives at the first distance Z0/2 in a configurationwhere stereoscopic display with four perspectives is achievable at thesecond distance Z0 (refer to FIG. 2) and pixel numbers to which theright-eye image is assigned in each of the sub-regions 31. A part (B) inFIG. 11 illustrates a correspondence relationship between a plurality ofsub-regions 31 configured in a manner similar to the case of the part(A) in FIG. 11 and pixel numbers to which the left-eye image is assignedin each of the sub-regions 31.

In the case where the view position of the viewer is located at thefirst distance Z0/2, the display control section 4 performs displaycontrol on the first to fourth pixels in each of the sub-regions 31(refer to FIG. 11) of the display section 6, independently, thereby tovary the correspondence relationship between the first to fourth pixelsand the perspective images (the right-eye image and the left-eye image)for each of the sub-regions 31. In this case, the display controlsection 4 assigns the right-eye image and the left-eye image to thefirst to fourth pixels in each of the sub-regions 31, and in the casewhere the view position of the viewer is located at the first distanceZ0/2, the display control section 4 assigns the right-eye image topixels which are viewable from the position of the right eye 10R andcorrespond to first to fourth light-convergence regions 11 to 14, andassigns the left-eye image to pixels which are viewable from theposition of the left eye 10L and correspond to the first to fourthlight-convergence regions 11 to 14. In the display section 6, eachsub-region includes first pixels to fourth pixels. The display controlsection 4 assigns the right-eye image to two successive (next to eachother or “adjacent”) pixels of the first pixel to the fourth pixel andassigns the left-eye image to other two successive (adjacent) pixels ofthe first pixel to the fourth pixels, in each sub-region. Moreover, acombination of the two (adjacent) pixels to which the right-eye image isassigned and a combination of the other two (adjacent) pixels to whichthe left-eye image is assigned vary from one sub-region to another.

More specifically, as illustrated in FIG. 11, for example, in a firstsub-region 31-1, the display control section 4 assigns the right-eyeimage to the first and second pixels, and assigns the left-eye image tothe third and fourth pixels. Moreover, in a second sub-region 31-2adjacent to the first sub-region 31-1, the display control section 4assigns the right-eye image to the second and third pixels, and assignsthe left-eye image to the first and fourth pixels.

Moreover, the display control section 4 performs control to movepositions in a horizontal direction of respective sub-regions (borders30 between a plurality of sub-regions 31) in response to movement in ahorizontal direction of the view position of the viewer.

FIG. 12 schematically illustrates a luminance distribution of each pixelin two adjacent sub-regions 31-1 and 31-2 in the case where stereoscopicdisplay as illustrated in the parts (A) and (B) in FIG. 11 is performed.In the case where the view position of the viewer is located at thefirst distance Z0/2, the display control section 4 performs displaycontrol to allow luminance of the first pixel and the third pixel to bethe lowest relatively with respect to that of the second pixel when aboundary portion between the first sub-region 31-1 and the secondsub-region 31-2 is viewed from the position of the right eye 10R and toallow luminance of the first pixel and the third pixel to be the lowestrelatively with respect to that of the fourth pixel when the boundaryportion is viewed from the position of the left eye 10L.

First Modification

In the above description, the case of stereoscopic display with fourperspectives is described as an example; however, the display accordingto the embodiment is applicable to the case where stereoscopic displaywith five or more perspectives is performed. FIGS. 13 to 15 illustratean example in the case where stereoscopic display with five perspectivesis performed. In this case, in accordance with five perspectives, firstto fifth numbers are assigned to a plurality of pixels (or sub-pixels)of the display section 6. In the case where the view position of theviewer is located at a preferred viewing distance (the second distanceZ0) with five perspectives, the display control section 4 assigns firstto fifth perspective images as a plurality of perspective images tofirst to fifth pixels in the entire screen of the display section 6, anddisplays the perspective images.

FIG. 13 illustrates viewable pixels in the case where the view positionof the viewer is located at a distance (the first distance Z0/2) equalto a half of the preferred viewing distance (the second distance Z0)with five perspectives when stereoscopic display with five perspectivesis performed. The right eye 10R is located in the first region 21 at thefirst distance Z0/2, and the left eye 10L is located in the secondregion 22 at the first distance Z0/2. The width of each of the firstregion 21 and the second region 22 is equal to the pupillary distance E(typically 65 mm).

In the case where the view position is located at the first distanceZ0/2, as illustrated in FIG. 13, light beams from the first to fifthpixels (first to fifth perspective images) reach the right eye 10R andthe left eye 10L.

A part (A) in FIG. 14 illustrates pixel numbers viewable by the righteye 10R and a luminance distribution in a viewing state illustrated inFIG. 13. A part (B) in FIG. 14 illustrates pixel numbers viewable by theleft eye 10L and a luminance distribution in the viewing stateillustrated in FIG. 13. In the viewing state illustrated in FIG. 13, theright eye 10R and the left eye 10L view pixels (perspective images)different from one of the four regions to another in the display section6. The width of each of the four regions is equal to the pupillarydistance E (typically 65 mm) More specifically, as illustrated in thepart (A) in FIG. 14, the right eye 10R views the third pixel (the thirdperspective image), the second pixel (the second perspective image), thefirst pixel (the first perspective image), and the fifth pixel (thefifth perspective image) in order from an end of the display screen.Moreover, as illustrated in the part (B) in FIG. 14, the left eye 10Lviews the fifth pixel (the fifth perspective image), the fourth pixel(the fourth perspective image), the third pixel (the third perspectiveimage), and the second pixel (the second perspective image) in orderfrom the end of the display screen.

As can be understood from the above description referring to FIGS. 13and 14, in the case where the view position is located at the firstdistance Z0/2, proper stereoscopic vision is not achieved while fiveperspective images, i.e., the first to fifth perspective images aredisplayed on the display section 6. Therefore, in the case where theview position is located at the first distance Z0/2, the display controlsection 4 controls the display section 6 to display two perspectiveimages, i.e., the right-eye image and the left-eye image instead of thefirst to fifth perspective images.

A part (A) in FIG. 15 illustrates a correspondence relationship betweena plurality of sub-regions 31 configured to allow stereoscopic displaywith two perspectives at the first distance Z0/2 in a configurationwhere stereoscopic display with five perspectives is achievable at thesecond distance Z0 and pixel numbers to which the right-eye image isassigned in each of the sub-regions 31. A part (B) in FIG. 15illustrates a correspondence relationship between a plurality ofsub-regions 31 configured in a manner similar to the case of the part(A) in FIG. 15 and pixel numbers to which the left-eye image is assignedin each of the sub-regions 31.

In the case where the view position of the viewer is located at thefirst distance Z0/2, the display control section 4 performs displaycontrol on the first to fifth pixels in each of the sub-regions 31 ofthe display section 6, independently, thereby to vary a correspondencerelationship between the first to fifth pixels and the perspectiveimages (the right-eye image and the left-eye image) for each of thesub-regions 31. In this case, the display control section 4 assigns theright-eye image and the left-eye image to the first to fifth pixels ineach of the sub-regions 31, and in the case where the view position ofthe viewer is located at the first distance Z0/2, the display controlsection 4 assigns the right-eye image to pixels which are viewable fromthe position of the right eye 10R and correspond to first to fifthlight-convergence regions 11 to 15, and assigns the left-eye image topixels which are viewable from the position of the left eye 10L andcorrespond to the first to fifth light-convergence regions 11 to 15. Inthe display section 6, each sub-region includes first pixels to fifthpixels. The display control section 4 assigns the right-eye image to twosuccessive (adjacent) pixels of the first pixel to the fifth pixel andassigns the left-eye image to other two successive (adjacent) pixels ofthe first pixel to the fifth pixel, in each sub-region. Moreover, acombination of the two (adjacent) pixels to which the right-eye image isassigned and a combination of the other two (adjacent) pixels to whichthe left-eye image is assigned vary from one sub-region to another. Aspecific method of assigning the images to the pixels is similar to thatin the case of the above-described stereoscopic display with fourperspectives.

Second Modification

A second modification relates to a method of reducing moiré (luminancenon-uniformity) occurring when optimized stereoscopic display isperformed in the case where the view position is located at the firstdistance Z0/2 as illustrated in FIGS. 11 and 12.

Parts (A) and (B) in FIG. 16 illustrate correspondence relationshipsbetween pixel numbers viewable by the right eye 10R and the left eye 10Land luminance distributions at the first distance Z0/2, as in the caseof the parts (A) and (B) in FIG. 10. As illustrated in FIG. 16, adecrease in luminance in a composite luminance distribution is caused inboundary portions between different pixels, and the decrease is observedas moiré. Therefore, in this modification, the display control section 4performs control to adjust a luminance level of one or both of twopixels in each of sub-regions (refer to FIG. 11) to uniformize luminancein each of the sub-regions. It is to be noted that the two pixels heremean two pixels in each of the right-eye image and the left-eye image.In other words, the two pixels mean two pixels to which the right-eyeimage is assigned as well as other two pixels to which the left-eyeimage is assigned.

FIG. 17A illustrate a first adjustment method adopted to suppressoccurrence of moiré. In the first adjustment method, a luminance levelof one or both of two pixels in each of the sub-regions is adjusted tobe increased. An increase in the luminance level is adjusted to allowthe luminance level in a central portion of each of the sub-regions tobe higher than that in a peripheral portion thereof. As illustrated in apart (A) in FIG. 18, for example, in the first sub-region 31-1,adjustment is performed to increase a luminance level of one or both ofa first pixel and a second pixel to which, for example, the right-eyeimage is assigned. Then, in the first sub-region 31-1, an increasedamount is adjusted to allow a luminance level in a central portion 33 tobe higher than that in a peripheral portion.

FIG. 17B illustrates a second adjustment method adopted to suppressoccurrence of moiré. In the second adjustment method, a luminance levelof one or both of two pixels in each of the sub-regions is adjusted tobe decreased. A decrease in the luminance level is adjusted to allow aluminance level in a peripheral portion of each of the sub-regions to behigher than that in a central portion thereof. As illustrated in a part(A) in FIG. 18, for example, in the first sub-region 31-1, adjustment isperformed to decrease the luminance level of one or both of the firstpixel and the second pixel to which, for example, the right-eye image isassigned. Then, in the first sub-region 31-1, a decreased amount isadjusted to allow the luminance level in the peripheral portion to behigher than that in the central portion 33.

A more specific example of the second adjustment method will bedescribed referring to FIG. 19. FIG. 19 illustrates an example of aluminance distribution of a first pixel and a second pixel in a regioncorresponding to the first sub-region 31-1 illustrated in the part (A)in FIG. 18. FIG. 19 also illustrates a moiré state. In FIG. 19, whenassuming that white display is performed as a whole, there is ageneration of luminance non-uniformity of 30% (0.9/0.68). Typically,luminance non-uniformity due to a luminance difference of 20% causesdiscomfort to the viewer. Therefore, it is necessary to reduce theluminance difference. To reduce moiré to 20% or less, luminance in aregion A in FIG. 19 is reduced by up to 8%. A maximum gray-scale numberis reduced from 254 gray-scale levels to 233 gray-scale levels togradually reduce a luminance adjustment width toward 0 to be close to aregion C, and in a similar manner, luminance in a region B is reduced byup to 5%, and a maximum gray-scale number is reduced from 254 gray-scalelevels to 242 gray-scale levels. Thus, moiré is allowed to be reducedbelow a perceptible level for the viewer.

[Effects]

As described above, in the display according to the embodiment, thenumber of perspective images assigned to the first to nth pixels and acorrespondence relationship between the first to nth pixels andperspective images are varied according to the view position of theviewer; therefore, optimum stereoscopic display according to the viewposition is allowed to be performed. The display according to theembodiment makes it possible to optimize display thereof only by imageprocessing. Thus, it is possible to readily work the display accordingto the embodiment without making movement or the like of the barrierdevice 7. Moreover, in the case where the view position of the viewer ismoved in a horizontal direction while the view position of the viewer islocated at the first distance Z0/2, it is only necessary to performcontrol to move the boundaries 30 between a plurality of sub-regions 31.Thus, it is possible to readily work the display according to theembodiment. Moreover, optimum display in consideration of the luminancedistribution as illustrated in FIG. 12 is performed; therefore, displaywith less crosstalk is allowed to be performed. In addition, it makes itpossible to establish a state in which image switching from one of aplurality of sub-regions 31 to another is difficult to be recognized;therefore, natural display for the viewer is allowed to be performed.

Moreover, in related art, when a space between a parallax separationstructure and a display section is too small, it is necessary to performglass grinding or the like to reduce the thickness of a glass substrateor the like between the parallax separation structure and the displaysection, thereby causing difficulty in manufacturing. In the displayaccording to the embodiment, the preferred viewing distance Z0 in designis allowed to be longer; therefore, a load caused by glass grinding isallowed to be reduced. A viewing distance in the case where display withtwo perspectives is performed in the display is equal to a half of anormal preferred viewing distance Z0 in design. In other words, apreferred viewing distance Z0 in design is allowed to be twice as longas that in a typical stereoscopic display method with two perspectives(refer to FIG. 3).

Other Embodiments

The present application is not limited to the above-describedembodiment, and may be variously modified.

For example, it is possible to achieve at least the followingconfigurations from the above-described exemplary embodiment and themodifications of the application.

-   (1) A display including:

a display section including a plurality of first pixels to a pluralityof nth pixels, where n is an integer of 4 or more, and displaying aplurality of perspective images assigned to the first to nth pixels; and

a display control section partitioning the display section into aplurality of sub-regions and performing display control on pixels ineach of the sub-regions, independently, thereby to vary a correspondencerelationship between the first to nth pixels and the perspective imagesfor each of the sub-regions,

wherein the display control section assigns a first perspective image totwo pixels of the first pixel to the nth pixel and assigns a secondperspective image to other two pixels of the first pixel to the nthpixel, in each of the sub-regions, and

the display control section adjusts a luminance level of one or both ofthe two pixels and a luminance level of one or both of the other twopixels in each of the sub-regions.

-   (2) The display according to (1), wherein the display control    section performs adjustment to increase the luminance level of one    or both of the two pixels and the luminance of one or both of the    other pixels, an amount of the adjustment allowing a luminance level    in a central portion of each of the sub-regions to be higher than a    luminance level in a peripheral portion thereof-   (3) The display according to (1), wherein the display control    section performs adjustment to decrease the luminance level of one    or both of the two pixels and the luminance level of one or both of    the other two pixels, an amount of the adjustment allowing a    luminance level in a peripheral portion of each of the sub-regions    to be higher than a luminance level in a central portion thereof-   (4) The display according to any one of (1) to (3), wherein the    display control section performs adjustment to uniformize the    luminance level within each of the sub-regions.-   (5) The display according to any one of (1) to (4), further    including a detection section detecting a view position of a viewer,

wherein the display control section varies the number of the pluralityof perspective images assigned to the first to nth pixels and varies acorrespondence relationship between the first to nth pixels and theperspective images, according to the view position of the viewer.

-   (6) The display according to (5), wherein the display control    section performs display control on pixels in each of the    sub-regions, independently, when the view position of the viewer is    located at a first distance from the display section.-   (7) The display according to (6), further including a separation    section separating light beams from the first to nth pixels to allow    the separated light beams to reach respective first to nth    light-convergence regions located at a second distance from the    display section,

wherein the display control section assigns first to nth perspectiveimages as the plurality of perspective images to the first to nth pixelsin an entire screen of the display section, when the view position ofthe viewer is located at the second distance.

-   (8) The display according to (7), wherein the first distance is    equal to a half of the second distance.-   (9) The display according to any one of (1) to (8), wherein the two    pixels are pixels next to each other.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The invention is claimed as follows:
 1. A display comprising: a displaysection including a plurality of first pixels to a plurality of nthpixels, where n is an integer of 4 or more, and displaying a pluralityof perspective images assigned to the first to nth pixels; and a displaycontrol section partitioning the display section into a plurality ofsub-regions and performing display control on pixels in each of thesub-regions, independently, thereby to vary a correspondencerelationship between the first to nth pixels and the perspective imagesfor each of the sub-regions, wherein the display control section assignsa first perspective image to two pixels of the first pixel to the nthpixel and assigns a second perspective image to other two pixels of thefirst pixel to the nth pixel, in each of the sub-regions, wherein thedisplay control section adjusts a luminance level of one or both of thetwo pixels and a luminance level of one or both of the other two pixelsin each of the sub-regions, wherein the sub-regions are partitioned atboundaries except for boundaries of pixels, wherein the sub-region for aright eye is different from that for a left eye, wherein two kinds ofcolor lights are emitted from two kinds of pixels of the sub-region forthe right eye, and another two kinds of color lights are emitted fromanother two kinds of pixels of the sub-region for the left eye, andwherein a luminance of at least one pixel of each the sub-region iscontrolled such that a degree of controlled luminance at approximatecenter of the sub-region is relatively greater than other area of thesub-region.
 2. The display according to claim 1, wherein the displaycontrol section performs adjustment to increase the luminance level ofone or both of the two pixels and the luminance of one or both of theother pixels, an amount of the adjustment allowing a luminance level ina central portion of each of the sub-regions to be higher than aluminance level in a peripheral portion thereof.
 3. The displayaccording to claim 1, wherein the display control section performsadjustment to decrease the luminance level of one or both of the twopixels and the luminance level of one or both of the other two pixels,an amount of the adjustment allowing a luminance level in a peripheralportion of each of the sub-regions to be higher than a luminance levelin a central portion thereof.
 4. The display according to claim 1,wherein the display control section performs adjustment to uniformizethe luminance level within each of the sub-regions.
 5. The displayaccording to claim 1, further comprising a detection section detecting aview position of a viewer, wherein the display control section variesthe number of the plurality of perspective images assigned to the firstto nth pixels and varies a correspondence relationship between the firstto nth pixels and the perspective images, according to the view positionof the viewer.
 6. The display according to claim 5, wherein the displaycontrol section performs display control on pixels in each of thesub-regions, independently, when the view position of the viewer islocated at a first distance from the display section.
 7. The displayaccording to claim 6, further comprising a separation section separatinglight beams from the first to nth pixels to allow the separated lightbeams to reach respective first to nth light-convergence regions locatedat a second distance from the display section, wherein the displaycontrol section assigns first to nth perspective images as the pluralityof perspective images to the first to nth pixels in an entire screen ofthe display section, when the view position of the viewer is located atthe second distance.
 8. The display according to claim 7, wherein thefirst distance is equal to a half of the second distance.
 9. The displayaccording to claim 1, wherein the two pixels are pixels next to eachother.